How is sync done from web browser?

How is synchronization managed from the web browser (toodledo.com web site)? I have been editing hundreds of tasks (nearly a thousand) in the last 2 days from two different laptops, changing status, title, context, folder, due dates and tags, and now I am going back through them with different types of searches I am finding many (at least several dozen) where some or all of the changes did not stick. I do not know whether I am looking at data that reflects what is on the server or bad caching on the browser.

Synchronization does not apply to changes that you make through the website from two different laptops. When you are accessing Toodledo through a browser there is only one place that your data is stored. (Toodledo backs up the server data but that's a different point.)

What types of changes are "not sticking"? Tasks, Contexts, Folders? All Tasks should be save automatically as soon as you leave the task.

The "Manage Folders" and "Manage Contexts" pages have a Save button. Perhaps you are not clicking it whenever you make a change.